Blast suppressor



Feb. 12, 195') M. RESSLER EI'L BLAST SUPPRESSOR Filed March 23, 1953 5 iNvENToRs MURRAY RESS/.ER HOWARD 5. HlLP'R/V United States Patent() BLAST sUPPREssoR Murray Ressier, silver spring, Minima Howard s. Haipern, Washington, D. C., assignors to the United States of America as represented by the Secretary of the Navy Application March 23, 1953, Serial No. 344,251

4 Claims.` (Cl. 89-14) (Granted under Title 3,5, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates 4to firearms and more particularly to an improved blast suppressor for eliminating blast destruction, reducing flash andshock front pressure at the muzzle end of a gun.

Blast deectors, silencers, and reducers have been devised heretofore through which a projectile is discharged which necessitated gradual enlarging rings progressively positioned within a cylindrical chamber to assure clearance for free passage for the fired projectile. Other devices utilized elongated slots with associated bar supports spaced to permit gas expansion about the bars through to the slots which also served as a guide means for the projectile without any provision for setting up turbulence within" the compartmented gas receiving chambers. However, in the prior art devices, any possible slight misalignment of the suppressor bore with the bore of the gun would cause disastrous results.

Baflles and bars in prior devices were used particularly to serve as ash hiders or `Suppressors and silencers because there was little if any concern for the shock front pressures encountered with the use of the old guns and propellants. However, the present trend in ordnance, wherein the use of modern propellants and projectiles cause shock front pressures of dangerous magnitudes, has required that Suppressors concentrate on the dissipation of the shock front pressures in addition to the objectives accomplished by the prior devices.

Many highly explosive projectiles employ extremely sensitive fuses that are armed prior to loading, as for use in aircraft guns and require unimpeded travel including sufficient lateral clearance yduring propulsion otherwise premature detonation may occur upon glancing contact within the conventional blast suppressor.l

An object of this invention is to eiectuate an ecient, reliable blast suppressor which will set up multiple wave reections and turbulence within the blast suppressor `to cause an appreciable reduction in the shock frontpressure accompanying projectile discharge. Y

A further object of this invention is to provide a device capable of gradually dissipating the harmful eiects attendant from the rapid expansion of the hot gases and the shock front pressure as a projectile is propulsed from the muzzle of a gun.

Still another object of this invention is to provide a suppressor that will guide a highly sensitive fused projectile thereby assuring against premature detonation.

The present invention overcomes the disadvantages of the prior art devices by providing a blast suppressor with a` tubular housing 'which encloses a group of spaced baille rings forming gas chambers or compartments within which the hot gases 'surrounding the projectile may expand rapidly to set up multiple wave reilections and turbulence thereby dissipating the accompanying shock front pressure, the gas velocity, and the rapidly expand- 2,780,962 Patented Feb.l1'2, 1957 ice ing gases surrounding the projectile. Longitudinal rods extending parallel to the axis of the gun bore and secured to the inner periphery of the bathe rings prevent the propelled projectile from impinging or ricochetting against the baille rings as it passes through the blast sup= pressor. By selectively spacing the rings and the ring supporting projectile guides separately compartmented gas chambers are formed and the missile is guided past each chamber without the danger of undue yawing or skewing before projecting into space. The rapidly expanding gases are retarded within the various chambersl and propel rather than impede the forward momentum of the missile.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. l is a longitudinal sectional view of a blast supf pressor shown with a projectile passing therethrough; and

Fig. 2 is a transverse sectional view taken along a line substantially corresponding to line 2 2 of Fig. l illustrating the internal spacing of the baille ring and rod framework positioned within the housing.

Referring to the drawings in the embodiment illustrated a tubular housing 10 encloses the internal cagelilce framework 11, all of which is formed sturdily and of a material which is capable of withstanding increased temperatures, pressures, and vibrations when subjected to the operation of rapid-lire discharge of projectiles. The housing diameter is designed to aiford suicient volume within the elongated length to provide a plurality of interconnected compartments which will gradually dissipate the increased pressures accompanying projectile discharge.

The cage-like compartmentation within the tubular housing 10 comprises a plurality of annular bale rings 12 spaced in accordance with the most desirable characteristics for the specific application. In the embodiment shown in Fig. l the rings 12 are spaced equally throughout the cylindrical cavity normal to the longitudinal axis of the housing 10 to form individual gas receiving chambers 13 through 18 which will dissipate the shock pressure front accompanying the projectile discharge. Each ring plate 12 as shown in Fig. l which constitutes one of the sides of the gas receiving chambers 13 through 18 is machined to engage concentrically the internal periphery of the tubular housing 10. Guide rods mounted within receiving holes or apertures 19 are drilled within each plate 12 which serve not only to guide the projectile 20 through the blast suppressor but also to support rigidly the inner periphery of the various ring baille plates 12in pla-ce.

A suitable manner for constructing the guide rod receiving ring plates 12 is to lay off the rod positions or holes 19 on a solid disk by inscribing a circle on the disk with a radius equal to the radius of the projectile 20 plus the requisite clearance desired between the projectile periphery when positioned suitably within the suppressor and a circle formed tangent to the inner peripheries of the guide rods 2l when positioned within the chambers 13 through 18. Guide rod supporting apertures 19 accommodating the guide rods 21 are drilled with the center of each aperture located at each apex of the vertices formed by the sides of an octagonal polygon. A central hole with a radius greater than the sum of the radii of the projectile 20 and the clearance required between the guide rod and the projectile but less than the radius measured from the center of the ring 12 to an apex of the octagonal polygon is drilled, thereby exposing each of the eight guide supporting apertures tothe inner periphery of the ring by approximately 90; The remaining arc within each. of the. guide supports 19 is suicient to provide adequate support for each of the guide rods 21 thereby preventing them from becoming disengaged', andv confining the projectile path but permitting free expansion of the longitudinal rods' 21v within thel blast suppressor housing 1i). Suitable fastening means of a more permanent nature may be used to maintain the guide rods 21 in position if necessary. However, frictionally supporting the guide rods throughout 270 at selected intervals affords sufficient support for maintaining the guide rods 21 in position within the bafe rings 12. Suitable results obtained by utilizing only half thenumber of guide rods 21 as provided for by the receiving holes 19 have been obtained. Upon wear and extended use replacement rods may be substituted for the worn rods or replacement rods may be inserted in the other remaining guide rod supporting apertures.

The guide rod apertures 19 serve to permit gas passage between compartments 13 through 1S as the pressure builds up within the rearmost chambers thereby rapidly dissipating the shockpressure front to the adjoining chambers as shown in Fig. 1. Insertion or removal of guide rods 21 will afford an appropriate means to regulate or dampen the dissipation of this shock pressure front between chambers.

To facilitate assemblage of the various components and assure alignment the longitudinal guide rods 21 are slidably inserted within the guide rod apertures 19 and the rings 12 are appropriately spaced, making up with cage-like structure 11.. Each rod 21 may be securely fastened as by spot-welding7 at one point on each rod to prevent longitudinal movement but to allow for the requisite expansion during operation. The cage-like struc- 'ture after assemblage is then inserted within the tubular casing or housing 10 affording a series of individual compartmentalized gas chambers 13 through 18 which are interconnected.

Fig. `l shows a means of retaining the aligned rings 12 within the housing 10. Countersunk. holes 22 circumfer entially spaced about the housing periphery for each baille ring 12 are used to locate the rings within the housing 10 and then are plug-welded thereby securing the rings 12 in permanent relationship. T he rings 12 formulating the sides of the gas receiving chambers 13 through 1S provide large surface areas which may also serve as radial fins to dissipate rapidly the khigh temperatures accompanying the massive gas discharge which follows the projectile 2d out of the muzzle of the gun 23, thereby reducing the gas pressures and volumes in accordance with the fundamental gas laws.

'Ihe foremost gas receiving chamber 13 may be `made devoid substantially of any longitudinal supporting guide rods 21. Escape ports may be drilled in the cylindrical tubular wall permitting gas to be released from the individual chambers within the blast suppressor to dissipate some of the intense pressure accompanying shell discharge. These ports are sulciently small and appropriately spaced so as not to permit an excessive gas discharge which will cause multiple small shock fronts about the gun. Depending on the blast suppressor application gas escape ports may be necessary to avoid excessive pressure buildup in rapid tiring operation or in relatively long blast Suppressors. The blast suppressor is readily adaptable vfor use in various caliber guns since it may be mounted directly on the gun muzzle thereby recoiling with the gun proper or it may be mounted on one end of a sleeve within which the gun barrel slides during recoil.

Operation of the blast suppressor may be visualized best by considering a projectile fired from the gun 23 as it emerges from the 'gun muzzle spinning about the longitudinal axis and propelled by the rapidly expanding s hot gases which follow and surround the boat tail and' base '24 'ofthe projectile 2t). Asy the ogive end '25 ,enters the blast suppressor the longitudinal `guide-rod 21,*wh1ch are circumferentially spaced, provide suticient clearance for normalyaw preventingpossible deflection into. the rings 12 which form the compartmented chambers 13 through 18. As the projectile 20 advances, thc hot expanding gases expand initially in the first open chamber 13 resulting in a reduction inpressure by providing a greater volume of gas expansion than the constricted volume within thebore of the Some heat is dissipated through the ring 12A toward the outer cylindriCal surface 10. Since the gas receiving compartmented chambers y13 through 13 are interconnected, expanding gases can infiltrate into the adjacent chambers through the space provided bythe extra rod apertures 19` and the annular cavity formed, between the projectile periphery and the ring plate 12 as the projectile passes through the chambers progressively therebyrestricting the forward movement of the gases. As part of the shock front impinges against the. leading baille ring 12 in chamber 13 the wave is reflected back by the same ring toward the cylindrical wall tol set up a turbulent mass front. This turbulent mass Willv attempt to disturb any laminar 'llow attendant beyondv the' wake of the projectile 2i). As thc projectile 20- advances to the next chamber 14, as gases expand' further, the attendant shock iront is reliected by the next ring 12 in chamber 14and the heat is dissipated within thechamber 14 to the ring plate 12 and so on throughout the length of the suppressor. As the projectile emerges from the discharge end'26 of the suppressor, the wave reections and turbulence induced by the ring plates 12 cause the one time disastrous shock front pressure to be reduced considerably from that evidenced at the muzzle area 23. Furthermore, the het gases having been detained now leave the blast suppressor with a lower velocity over a longer interval of time than they leave thc muzzle ol. the gun.

Obviously runny modifications and variations of the present invention are possible in the light or the above teachings. lt is therefore to be understood that within the scope of the appended claims the invention may be practiced' otherwise than as specically described.

WhatY is claimed is:

l. A blast suppressor for rapid .dre guns comprising; an elongated cylinder, a plurality lof spaced notched rings mounted therein and forming a plurality of separate chambers with openings interconnecting adjacent chambers, a plurality of spaced longitudinally extending rods connected to the inner periphery of said rings andl forming an open-ended suspended cage, said rods having a .substantial portion thereof extending beyond said inner periphery of said rings for engaging and guiding the passage of a projectile therethrough in spaced relation with respect to said inner periphery of the rings, and said notches connecting each chamber for progressivelyy dissipating the shock wave and high pressure projectile gases by expansion and turbulence therein.

2. A blast suppressor mounted on the muzzle end of a gun through which a projectile is *fired comprising; an elongated tubular housing, plate baille rings selectively spaced `within the tubular housing forming compartmented vinterconnected gas receiving chambers, and a plurality of longitudinal disposed rods spaced about the inner periphery of said rings, said'rods having a substantial portion thereof extending beyond said inner peripl ery of the rings *for-engaging and guiding Ithe yprojectile through the suppressor chambers Iandv rings in spaced relation with respect `to the inner periphery of the rings whereby-the shockwave and highpressuregases attending projectile discharge are progressively dissipated by turbulence and expansion therein.

3. A `blast suppressor mounted on the -rnuzzle Ao a gun through which a vprojectile is tired comprising; an elongatedfcylindrical tube, rings lselectively .spaced within the tube forming compartmented interconnecting vgas reee'iving chambers, and a1plurality of .spaced longitudinal rods ldiametrically 1opposed about f-the yinner .periphery of said rings, :saidrodshavin g a l substantial portion .there AEi of extending beyond said inner periphery of the ring for engaging and guiding the projectile through the suppressor chambers and rings in spaced relation with respect to the inner periphery of the m'ngs whereby the shock wave and high pressure gases 1attending projectile discharge are progressively dissipated by turbulence and expansion therein.

4. For use in a tubular blast suppressor to be mounted on the muzzle end of a gun through which a projectile is fired, an assembly comprising; a plurality of spaced rings mounted to form a ser-ies of gas deflector bafes, a plurality of spaced longitudinally extending rods connected to the inner periphery of said rings forming an open-ended cage, said rod having a substantial portion thereby extending beyond said inner periphery of the References Cited in the file of this patent UNITED STATES PATENTS 2,101,848 Green Dec. 14, 1937V 2,444,910 Barker July 13, 1948 FOREIGN PATENTS 858,032 France Mar. 6, 1940 

